<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box{
      width: 1000px;
      height: 400px;
      background-color: orange;
    }
    .box strong{
      float: left;
      /* position: fixed;
      left: 0; */
    }
  </style>
</head>
<body>
  <div class="box">
    <span>我是span元素</span>
    <strong>我是strong元素</strong>
    <i>我是i元素</i>
    <div>我是普通的内容</div>
  </div>
</body>
</html>